All Tables
- Table 1:
Summary of HESS observations of RX J1713.7-3946 conducted during
three years. For each year, the targeted position is given
together with the wobble offsets in Right Ascension
and Declination
.
Adding the wobble offsets to the target
coordinates, the actual pointing position is obtained. For each
pointing position, the dead-time corrected observation time
(Live time) is given in hours. Data recorded under bad
weather conditions are excluded. The columns Data set
I-III summarise observation times of data sub-sets used
throughout the paper. Data set I is used for
Fig. 2; to obtain optimum angular
resolution, the 2003 data are disregarded and a zenith-angle cut
at
is applied (the latter is only relevant for the
2005 data). Data set II is used for spectral comparisons
of the different years (cf. Fig. 3). Observations with wobble
offsets of
in 2004 and 2005 are disregarded for this
purpose. Data set III comprises all data, and is used for
the generation of the combined spectrum (cf. Fig. 4).
- Table 2:
Summarised are the event statistics of the whole SNR and
corresponding angular resolutions for the years 2003, 2004, and
2005. The 2004 and 2005 data sets correspond to Data set
I of Table 1.
The average zenith angle
is determined from all events
reconstructed in the SNR region. For the angular resolution
(R68), the 68% containment radius of the
simulated gamma-ray point-spread function, matched to the
particular data set, is used as figure of merit. The
other columns give the number of signal events from the SNR
region (ON), the number of background events (OFF), the
normalisation factor between ON and OFF counts (
), and
the corresponding significance and live observation
time.
is in general defined as the ratio of the
effective exposure integrated in time and angular space of the
ON and OFF region. Note that the analysis of the 2003 data is
adopted to match the system configuration of this year. The
nominal analysis is applied for the 2004 and 2005 data. For
2005, only data recorded at zenith angles less than
are included (therefore the mean zenith angle decreases). The
event statistics are determined with the ON/OFF approach
for 2003 and the reflected-region method for 2004 and
2005. In the latter two years, also ON runs with wobble
offsets <
(cf. Table 1)
are
included and hence
.
- Table 3:
Comparison of event statistics from the SNR region from
three years of data. The numbers result from the spectral
analysis of Data set II (cf. Table 1),
shown in
Fig. 3. Given are the number of signal
(ON) and background (OFF) counts, the
normalisation factor
,
the statistical significance of
the gamma-ray excess (
)
and the observation time. For
the 2003 data, the special two-telescope analysis with a cut on
the minimum size of camera images at 300 photo-electrons was
applied. The background estimate in this case is derived with
the ON/OFF analysis. For 2004 and 2005, the nominal
spectral analysis with a cut at 80 photo-electrons was used
together with reflected-region background model.
- Table 4:
Fit results for different spectral models. The fit range
is chosen from 0.3 to 113 TeV. The differential flux normalisation
I0 is given in units of
.
Shown are a power-law model
(row 1), a power law with an exponential cutoff (row 2, 3, 4; the
cutoff energy
is given in TeV), a power law with an
energy dependent photon index (row 5), and a broken power law (row
6; in the formula, the parameter S = 0.6 describes the sharpness
of the transition from
to
and it is fixed in
the fit). Note that when fitting a broken power law to the data,
some of the fit parameters are highly correlated.
- Table 5:
Flux points including relevant event statistics are
listed for the spectrum of the combined HESS data set, shown
in Fig. 4. For all 28 bins, the energy,
the number of signal and background counts (ON and OFF), the
normalisation factor
,
the statistical significance
,
the gamma-ray flux and the energy range of the bin are
given. The significance is calculated following
Li & Ma (1983). For the final bin, as it has only marginally
positive significance, we list both the actual flux point and
the
upper limit (which is drawn in
Fig. 4). Note that the energy and flux
values given here are corrected for the variation of optical
efficiency, as discussed in the main text.